I can highly recommend the java.util.concurrent classes of JDK 5, I've been porting from concurrent.jar to them in JGroups for the last weeks, and I get performance optimizations of roughly 10%. Besides, I expect to scale much better on multi core machines, this requires some additional work on my behalf though, like lock striping, use of atomic updates rather than synchronization etc etc etc. I can highly recommend Brian Goetz' book "Java Concurrency in Practice" which discusses the java.util.concurrent lib, but also presents tips and tricks on concurrent programming best practices in general Emmanuel Bernard wrote: -- Bela Ban Lead JGroups / JBoss Clustering team JBoss - a division of Red Hat

We have wrappers around the Lea concurrent package, but for java5 based stuff have been switching to using the java.util.concurrent in java5. Emmanuel Bernard wrote: